From: "Alexey V. Vissarionov" <gremlin@altlinux.org>
To: Jon Hunter <jonathanh@nvidia.com>
Cc: "Alexey V. Vissarionov" <gremlin@altlinux.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Thierry Reding <thierry.reding@gmail.com>,
Uwe Kleine-Knig <u.kleine-koenig@baylibre.com>,
Nagarjuna Kristam <nkristam@nvidia.com>,
linux-usb@vger.kernel.org, linux-tegra@vger.kernel.org,
lvc-project@linuxtesting.org
Subject: Re: [PATCH v1] usb: tegra-xudc: check ep and ep->desc before deref
Date: Wed, 16 Apr 2025 14:54:16 +0300 [thread overview]
Message-ID: <20250416115416.GC27292@altlinux.org> (raw)
In-Reply-To: <6e0b8bb7-c9c4-4625-bad0-552dcad89ea0@nvidia.com>
Good ${greeting_time}!
On 2025-04-16 11:20:10 +0100, Jon Hunter wrote:
>> + /* trb_phys_to_virt() dereferences ep; check it here */
>> + if (!ep)
>> + {
> Please make sure you run 'checkpatch.pl' as I am sure if will
> flag that the above should be ...
> if (!ep) {
ACK.
>> + dev_err(xudc->dev, "Unbelievable: ep is NULL\n");
> I quite like the 'Unbelievable' but 'unexpected NULL pointer
> for ep' is also fine.
ACK.
>> + /* tegra_xudc_req_done() dereferences ep->desc; check it
>> here */
>> + if (!ep->desc)
> I am not sure about the error message here, because the existing
> code just skips this. So it is not clear if this can happen and
> could be expected.
Now ep->desc is checked immediately after tegra_xudc_req_done(),
where it is dereferenced, so it was somehow expected. My suggestion
is just to check this expection earlier.
Next version of the patch follows.
--
Alexey V. Vissarionov
gremlin ПРИ altlinux ТЧК org; +vii-cmiii-ccxxix-lxxix-xlii
GPG: 0D92F19E1C0DC36E27F61A29CD17E2B43D879005 @ hkp://keys.gnupg.net
next prev parent reply other threads:[~2025-04-16 11:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-15 17:42 [PATCH] usb: tegra-xudc: check ep->desc before dereferencing Alexey V. Vissarionov
2025-04-16 7:43 ` Jon Hunter
2025-04-16 9:53 ` Alexey V. Vissarionov
2025-04-16 9:55 ` [PATCH v1] usb: tegra-xudc: check ep and ep->desc before deref Alexey V. Vissarionov
2025-04-16 10:20 ` Jon Hunter
2025-04-16 11:54 ` Alexey V. Vissarionov [this message]
2025-04-16 12:00 ` [PATCH v2] " Alexey V. Vissarionov
2025-04-16 14:13 ` Alan Stern
2025-04-21 15:07 ` Alexey V. Vissarionov
2025-04-21 15:41 ` Alan Stern
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